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IRCT20260923071166N1 IRCT 2026-09-30 Iran University of Medical Sciences Comparing Effects of Non-Invasive Direct and Alternating Current Brain Stimulation on Motor Learning Direct current brain stimulation: tDCS, Alternating Current Brain Stimulation: tACS Comparing Short- and Long-term Effects of Non-Invasive Direct and Alternating Current Brain Stimulation at Theta, Beta and Gamma Frequencies on Motor Learning in Healthy Adults 2026-10-22 anticipated 75 Recruiting https://irct.ir/trial/93557 interventional Randomization: Not randomized, Blinding: Single blinded, Placebo: Used, Assignment: Parallel, Purpose: Supportive, Blinding description: Numbered, sealed, opaque envelopes will be used for allocation concealment and will be provided to participants by the study secretary. Participants will be blinded to their group allocation and will not know whether they have been assigned to the sham control group or one of the active intervention groups. The therapist administering the intervention and the outcome assessor will not be blinded. N/A Motor Learning. Intervention 1: Intervention group: Participants in the transcranial direct current stimulation (tDCS) group will receive stimulation at an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm². The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Intervention 2: Intervention group: Participants in the transcranial alternating current stimulation (tACS) group will receive stimulation at a frequency of 5 Hz and an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm², with a 30-second ramp-up and a 30-second ramp-down. The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Intervention 3: Intervention group: Participants in the transcranial alternating current stimulation (tACS) group will receive stimulation at a frequency of 20 Hz and an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm², with a 30-second ramp-up and a 30-second ramp-down. The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Intervention 4: Intervention group: Participants in the transcranial alternating current stimulation (tACS) group will receive stimulation at a frequency of 70 Hz and an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm², with a 30-second ramp-up and a 30-second ramp-down. The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Intervention 5: Control group: Participants will receive stimulation at an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm². The stimulation will be discontinued after a 30-second ramp-up period. The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is No further information is available
public Fatemeh Askari chenari
No. 35, alley 33, Imam musa kazem street, Eslamshahr
Eslamshahr Iran (Islamic Republic of) 3313794575 +98 21 5636 9803 Fatemeh80.a@gmail.com Iran University of Medical Sciences scientific Roya KhanMohammadi
Madadkaran Street, Shah Nazari Street, Mother Square, Mirdamad, Tehran
Tehran Iran (Islamic Republic of) 1348715459 +98 21 2222 7124 Dr.rkhanmohammadi96@gmail.com Iran University of Medical Sciences Iran (Islamic Republic of) Healthy individuals (both sexes) Age 18–40 years No history of neurological disorders, including epilepsy and seizures, traumatic brain injury, or migraine No orthopedic, neurological, or rheumatological injury/disorder that limits the upper extremity No cognitive or perceptual impairments (Mini-Mental State Examination more than 24) No uncorrected visual impairments No use of medications affecting the central nervous system No psychiatric disorders such as anxiety or depression requiring medication No vigorous physical activity within two hours prior to the experiment No consumption of coffee or caffeine within two hours prior to the experiment No history of activities requiring high manual dexterity, such as playing the piano, or playing video games Not pregnant No sleep disorders No intracranial implants or cardiac pacemakers 18 years 40 years Both Unwillingness to cooperate Conscious memorization of the sequence and its correct recall Rehabilitation Rehabilitation Rehabilitation Rehabilitation Rehabilitation Intervention group: Participants in the transcranial direct current stimulation (tDCS) group will receive stimulation at an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm². The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Intervention group: Participants in the transcranial alternating current stimulation (tACS) group will receive stimulation at a frequency of 5 Hz and an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm², with a 30-second ramp-up and a 30-second ramp-down. The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Intervention group: Participants in the transcranial alternating current stimulation (tACS) group will receive stimulation at a frequency of 20 Hz and an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm², with a 30-second ramp-up and a 30-second ramp-down. The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Intervention group: Participants in the transcranial alternating current stimulation (tACS) group will receive stimulation at a frequency of 70 Hz and an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm², with a 30-second ramp-up and a 30-second ramp-down. The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Control group: Participants will receive stimulation at an intensity of 1 mA, corresponding to a current density of 0.05 mA/cm². The stimulation will be discontinued after a 30-second ramp-up period. The active electrode will be placed over the primary motor cortex (M1) of the dominant hemisphere, while the reference electrode will be placed over the supraorbital area contralateral to the non-dominant hand. Mean reaction time (RT). Timepoint: Reaction time: Assessed at baseline, 35 minutes after stimulation, and 48 hours after stimulation. Method of measurement: Reaction time Defined as the time interval between the presentation of the stimulus and the participant’s correct response. Mean response accuracy. Timepoint: Response accuracy: Assessed at baseline, 35 minutes after stimulation, and 48 hours after stimulation. Method of measurement: Response accuracy Defined based on responses corresponding to the position of the black circle. Normalized skill index (NSI). Timepoint: Normalized skill index Assessed at baseline, 35 minutes after stimulation, and 48 hours after stimulation. Method of measurement: It is calculated as the number of correct responses in each block divided by the total number of responses (correct + incorrect), multiplied by 100. Iran University of Medical Sciences Approved 2026-08-18 Research Ethics Committees of School of Rehabilitation Sciences, Iran University of Medical Sciences Research and Technology Deputy, Iran University of Medical Sciences, Hemmat Expressway Tehran Tehran Iran (Islamic Republic of)